Steam-boiler and furnace



(No Model.) 2: SheetsfSheet 1.

W. HOPKINS. STEAM BOILER AND FURNAGE THBBBFOR..

No. 605,427. Patented June '7, 1898.

/N VENTO i Arron/ver WASHINGTON o c 2 Sheets-Sheet 2.

(No Model.)

W. HOPKINS. STEAM BOILER AND PURNAGE THBRBPUR.

Patented June 7,1898.

A TTU/SWE YS.

Unirnn @raras il .ar-nr ninna VILLIAM HOPKINS, OF DUBUQE, 4IOVA.

STEAM-Bomen' AND i-'uRNAeEri-IEREFOR.

SPECIFICATION forming part of Letters Patent 1\T o. 605,427, dated June '7, 1898. Application filed September 14, 1897. Serial No. 651,656. (No model.)

T0 ctZZIl/tom it may concern:

Be it known that I, WILLIAM HOPKINS, of

n Dubuque, in the county of Dubuque and `State i of Iowa, have Yinvented a new and Improved i Steam-Boiler and Furnace Therefor, of which the following is a full,- clear, and exact description.

This invention relates to steam-boilers of the horizontal fire-tube type, having a firechamber extending longitudinally below the boiler-shell.

One object of my invention Yis to provide a steam-boiler of the `indicated type with one. or more tubular fire-chambers orfur'naees, each having an annular water-space extending throughout the length of the furnace and connecting said annular water-space near` each end of the furnace and boiler with the 1 shell of the latter in a manner which will insure a rapid continuous water circulation throughout the interiorof the steam-boiler;

thus assuring its maximum efficiency as a` steam-generator and obviating strains due to unequal expansion of material composing the boiler. y A further object is to provide the tubular fire-chamber or furnace for the steam-boiler with a corrugated interior fire-wall that is essentially cylindrical and held concentricwith'- in the exterior shell of the furnace, thereby affording an annular water-space around the cylindric fire-wall, which is to be branch-connected by thimbles or like means with the water-space in the boiler to establish free water circulation between the water -holding compartment of the furnace and the water-` space of the boiler. A I

The invention further comprehends the provision of one or more water-circulating pipesextended between the annular'water` space ofthe furnace and the interior of" the boiler, said tubular conduit being exposed to the heat of the furnace, whereby the temperature of the water passing upward through the said `pipe will beraised before it enters the boiler. Furthermore,the feed-Water passing froma cold-water supply is introduced withinthe lower portion of the upright circulating-pipmwhereby said feed-water is commingled with the water circulating between is thus heated before its introduction within thel steam-boiler.

n In attaining the indicated objects the invention consistsof certain details ofconstruction andcombinations of parts7 as is hereinafter described, and defined in the Aappended claim.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters 0f reference indicate corresponding parts in both figures.

Figure l is a rear end elevation of the improved steam-generator device, and Fig. 2 is a sectional side view taken substantially on the line 2 2 in Fig. l.y

In the drawings7 that illustrate an embodimentof the featuresof the improvement, 5 indicates the cylindrical shell of the steamboileryand l6 the` exterior shell Vof the furnaces, two of which are represented in Fig. l. While it is preferred to furnish a steamboiler of considerable `diameter with two of the improved furnaces, itis to be understood that a single furnace may be employed if 1 the boiler and water-space in the furnace and suitable relative dimensions are vafforded to adapt one furnace for sufficient service in connection with said boiler. f

`The boiler-shell 5M's closed at each end by the flue-sheets 7 8, peripherally flanged in the usual way, andvsecured in place, respectively, latthe front and 4rear ends of said shell by rivets or equivalent means.

As'uitable number of fines 9is held within the shell 5 and longitudinally extended therethrough `by-a fixed engagement of the ends of said fines within spaced perforations formed inthe `flue-sheets 7 8. The several series of fines are so disposed within the boiler as to afford an adequate steam-space A above them 4and also a water-space surrounding the nest of lues to'provide for the circulation of water between the outer iiues of each row and the inner surface of the boiler-shell, as usual.

In the steam-space A stay-bolts l0 extend longitudinally between the flue-sheets 7 8, and are secured in said flue-sheets by set-nuts or other means. One or more braces Il may be extended from the front nue-sheet 7 to the crown ofthe `boiler-shell and secured thereto,

as shown in Fig. 2. The two similar furnaceshells 6 are of substantially the same length as the boiler-shell 5 and are of less diameter than said shell. Within each of the furnaceshells 6 a cylindrical plate-metal fire-wall 12 is secured, having such decreased diameter as will produce an annular water-space B between the {ire-Walls and the shells.

A preferred means for spacing and securing the ends of the fire-wall 12 to the exterior furnace-shell 6 is shown in Fig. 2. Said means consists in the provision of a spacing-ring 13 for each end of the furnace, which rings may be formed of sheet metal, each having a peripheral flange and also a flange formed at theinner edge of the ring, both of said flanges on each spacing-rin g being adapted to closely contact, respectively, with an end portion of the shell 6 and of the fire-wall 12 and are se- 'cured thereto by rivets or other equivalent means. p

Preferably the plate-metal cylindrc firewall 12 in each furnace is corrugated, whereby a greatly-increased heating-surface is afforded and the wall is strengthened and stiffened sufliciently to render it unnecessary to employ stay-bolts between the fire-wall and eX- terior shell 6.

Near each end of the boiler-shell 5 and the 'corresponding ends of the similar furnaceshell 6 suitable apertures are formed in these shells, and the furnace-shells are joined to the boiler-shell at a proper distance from each Vother on the lower side of the boiler-shell by rings or thimbles 14, attached to the shells 6 and 12 by any preferred means, the thimbles encircling the apertures in the shells, thus affording free passages for water at each end of each furnace and the boiler.

Preferably the thimble at the rear end of each furnace-shell 6 is made somewhat shorter than the forward thimble, which will cause the upper side of each furnace-shell 6 to ineline from front to rear, as indicated in Fig. 2.

In each compartment produced within the cylindric wall 12 a transverse bridge-Wall 15 is located at a proper distance from the front end of the furnace, said wall being constructed of lire-brick or other refractory material, and masonry or other filling material is introduced behind the bridge-wall of a suitable height to form a draft-passage C, which extends from the bridge-wall 15 to the rear end of the fire-wall 12.

Transverse bearing-bars 16 17 are respectively affixed at the front of the bridge-wall 15 and the front end of the fire-wall 12, which bars afford support for a series of grate-bars 18, thus providing a combustion-chamber D above the gratos and an ash-pit E below the` same.

When the complete steam generator is erected at any locality for service, the boiler `and furnaces are inclosed with masonry walls The rear ends of the boiler-fines 9 are connected with the rear end of the draft Hue or passage C by a flue extension C', which may be formed of masonry or other material, and

` it will be seen that the products of combustion which pass over the bridge-wall 15 will be drawn rearwardly and upwardly through the passage C C and thence forwardly through the flues 9 to heat the water in the shell 5 and evolve steam therefrom.

In the lowermost portion of the annular water-space in each furnace, at the rear end of the same, one end of an upwardly-bent branch water-pipe 19 is secured, these pipes being joined at their upper ends to the body of the upright water-feed pipe 20, which is shown broken at its lower end, but which is designed in service to be extended to a source of water-supply under pressure.

Above the point where the branch pipes 19 join the feed-pipe 20 the latter is upwardly projected through the draft-flue extension C', as shown in Fig. 2. Above said upright ilue C the water-supply pipe 2O is bent at a right angle to extend it forwardly through the rear flue-sheet 8 of the boiler, wherein it is rendered steam-tight by any preferred means, and said pipe is projected toward the front flue-sheet 7, terminating near the latter in an L, that discharges downwardly. Preferably the water-feed pipe 2O is constructed of Vtwo sections, which are joined together by the union-fitting 21.

In each branch water-pipe 19 a check-valve 19a of ordinary construction is introduced, as shown in Fig. 2, these valves being provided to prevent a current of cold water from passing through the branch pipes into the rear ends of the annular water-spaces B when feed water is periodically passing through the pipe 20, as may be necessary to keep a proper quantity of water in the boiler.

Assuming that the improved steam-generating apparatus is erected as specified and is in operative condition, it will be seen that when a proper quantity of water is introduced within the boiler-shell 5 and the water-spaces B in the furnaces the products of combustion evolved from the fire in the chambers D will pass rearwardly in contact with all the interior surface of the fire-walls 12 above the grate-bars and the lower surface of the draftpassages C and pass thence forwardly through the tubular flues 9, as before mentioned. The heat applied to the upper portion of each fire-wall 12 will quickly raise the tempera- IOO IIO

IZO

ture of the water held in the annular spaces B, and as the crowns of the shells 6 incline from front to rear it will be evident that water immediately over the iires in the chambers D and that is most quickly heated thereby will be rarefied and pass rearward and then upward through the rear thimbles 14. After entering the boiler-shell 5 through the rear thimbles 14 the intensely-heated water passes upwardly and forwardly between the lues 9, from which it receives additional heat, and steam generated thereby occupies the space A. The current of water from the rear end of the boiler is measurably cooled by water that passes up through the branch pipes i9 and feed-pipe 20 from the lower part of the annular chambers B. Now as the partly-cooled water becomes heavier it descends through the forward thimbles 14 into the spaces B to again become highly heated from contact with the crowns of the fire-walls 12 and thence passes rearwardly, thus estab` lishing a continuous uniform circulation in the furnace and boiler-shell for the copious generation of high-pressure steam, the direction of` water circulation being clearly indicated by arrows in Fig. 2.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- A boiler having a cylindrical boiler-shell, a series of ire-tubes run through said shell, two exterior furnace-shells located beneath the boiler-shell and running parallel therewith and communicating therewith at each end, a fire-wall within each furnace-shell, the spaces inclosed by the front portions of the yfire-walls serving as fire-boxes, means engaging said shells and forming a passage establishing communication between the iirewalls and the'iire-tubes of the boiler-shell,

and pipes passing respectively from the rear l bottom portion of each furnace-shell upward to the upper portion of the boiler-shell whereby to lead the water from said lower rear portions back to the boiler-shell.

VILLIAM HOPKINS. NVitnesses:

E. M. DICKEY, F. G. I-IoRNBoGEN. 

